Device for Redirecting the Luminous Flux Emitted by One or More LED

ABSTRACT

The invention relates to a device for redistributing with axis rotated to 90° of the luminous flow emitted by one or more LEDs as secondary optical component for the construction of sources, lamps, illuminating bodies, and solid state optical signalling apparatuses. In one of its basic forms the invention comprises a main optical element ( 1 ) and an optical protection case ( 20 ) coupled by a pin ( 5 ) obtained in the element ( 1 ) and a cavity ( 21 ) obtained in the case ( 20 ).

The present invention relates to a device for redirecting the luminousflow emitted by one or more LEDs as a secondary optical component forthe construction of sources, lamps, illuminating bodies and solid stateoptical signalling apparatuses.

The object of the present invention is to obtain with the lowestpossible fabrication costs with respect to what is known in the priorart and available commercially a device for redistributing the luminousflow emitted by one or more LEDs in such a way that the optical axis isrotated by 90 and at the same time the emission angles can be variedrelative to said axis.

In the most general form, all current devices for redistributing theluminous flow with rotation of the optical axis to 90° for LED emittersprovide for the use of conical solid structures with vertex reversed andoriented towards the upper part of the primary lenses integral with theLED emitters.

An additional characterisation of the devices currently in use is thattheir conical shape is typically supported by a hollow cylindricalstructure within which are located the LEDs and which is fastened to theouter edge of said emitter or to the surface/structure whereon they arepositioned.

Further variants of the devices currently in use provide for the use orthe modification of primary lenses so that at the top of the standardconvex shape of the surface of said lenses is obtained a depression withconical shape with vertex towards the junction to semiconductor emitterof the luminous flow.

The main object of the present invention is to provide superiorfunctional performance with respect to the prior art in relation to thecapability of also defining differently the angles of emission above andbelow the optical axis rotated by 90° with respect to that of the LEDemitters and at the same time of obtaining a greater intensity ofemission due to the mutually combined functionalities of opticalreflection and refraction.

A further advantage of the invention, since it has no direct connectionto the LEDs is that it can be inserted within optical protection casestypically in use in lamps and thereby to allow their easy replacement ifrequired for maintenance reasons or because of changed requirements ofthe redistribution of the luminous flow by virtue of the connection byconical insertion or in snap-in fashion.

These objects and advantages are all achieved by the invention inquestion as it is characterised by the appended claims.

Additional characteristics and advantages of the present invention willbecome more readily apparent from the following detailed description ofpreferred, but not exclusive, embodiments of the invention, all based onthe same principle and illustrated purely by way of non limiting examplein the accompanying figures, in which:

FIG. 1 shows the section view of the invention comprising the set of itselements among which the optical protection case (where for the sake ofillustration clarity the usual dashed lines are omitted) coupled onto acharacteristic solid state source shown in a lateral view;

FIG. 2 shows a variant of the invention shown in the same way as FIG. 1and characterised by an additional reflecting/diffusing element and byan additional spacer element;

FIG. 3 shows an additional variant of the invention shown in the sameway as FIG. 2 and characterised by an additional element for connectingto the optical protection case;

FIG. 4 shows the invention of FIG. 1 in which with dashed lines areshown the modifications made to the distribution of the main luminousflow produced by the LED emitters.

With reference to the aforementioned figures, the numeral 1 indicatesthe main optical element of invention, 20 the optical protection case,40 an optional reflector/diffuser, 50 an optional spacer element, 60 analternative separate connection element, 30 a typical commercial solidstate source.

With reference to FIG. 1, the conformation of the main optical element1, preferably but not exclusively made of optical grade polycarbonate,for the purposes of redistributing the luminous flow according to whatis described above and shown in FIG. 4 with the reference number 100 isachieved by:

-   a profile indicated by the number 2 that inferiorly by revolution    around the axis of symmetry defines a surface characterising a    conical cavity with the vertex positioned in opposite direction    relative to the primary lenses of the LEDs indicated by the number    34 (unlike what is found in products currently available on the    market and according to the prior art),-   a profile indicated by the number 4 that superiorly by revolution    around the axis of symmetry defines a surface characterising a    cupola-shaped cavity with the vertex positioned in the direction of    the primary lenses of the LEDs indicated with the number 34;-   a profile indicated by the number 3 that laterally by revolution    around the axis of symmetry defines a surface characterising a cone    frustum shaped solid with the vertex positioned in the direction of    the primary lenses of the LEDs indicated by the number 34.

With reference to FIG. 1, the number 5 indicates a cylindrical pinpreferably with slight conicity obtained as an appendage of the element1.

With reference to FIG. 1, the number 21 indicates a cylindrical cavity,preferably with slight conicity located inside the thickened region 23of the optical protection case 20 to house the pin 5 and achieve themechanical coupling between the elements 20 and 1.

In relation to the optical protection case 20 of FIG. 1, preferably butnot exclusively made of optical grade polycarbonate, the thickenedregion at the top 23 has an inner surface 22 that is convex towards theinner cavity 24. Said convex surface 22 is preferably made in such a wayas to obtained a diffuse reflection.

With reference to FIG. 1, the number 33 indicates the edge forfastening, in snap-in fashion or by screw or with other means, thecommercial solid state source 30 with the elements 20 and 1 previouslycoupled to each other by insertion in the hollow region 24.

Also with reference to FIG. 1, the commercial solid state source 30 mayalso be of the type lacking the adapter ring 32 and constituted by thesole electrical attachment 31 comprehensive of the electrical/electroniccircuits for controlling the current to the LED emitters 34. Thispossibility, not shown in the figures, entails that the edge of theelectrical attachment serves the same function as the edge 33 of theadapter ring 32 for the purposes of fastening, in snap-in or screw-infashion, or by other means, to the optical elements 20 and 1.

With reference to FIG. 2, as an embodiment variant of the inventionindicated in FIG. 1, the reference 40 indicates a reflector/diffuserelement having a convex surface 41 of the specular reflecting or diffusereflecting type.

The element 40, made of metallic or plastic material with addedmetal-coating, will be positioned by the element 1 at a distancepredetermined by means of a spacer element 50.

In some additional embodiment, not shown, the spacer element 50 may beobtained as an appendage of the reflector/diffuser element 40 oralternatively to the main optical element 1.

With reference to FIG. 2, the remaining elements shown serve the samepurpose indicated for the those of FIG. 1, whereto the reader isreferred for their description.

With reference to FIG. 3, as an additional embodiment of the inventionof FIG. 2, the number 6 indicates a hole at the centre of the mainoptical element 1 instead of the cylindrical pin 5 into which isinserted, during the coupling with the optical protection case 20, apreferably metallic pin 60, with its surface preferably nickel- orchrome-plated, provided with retaining head 61 to reduce the slightluminous flow dispersed in the direction of the optical axis of the LEDs34.

With reference to FIG. 3, the remaining elements shown serve the samefunction indicated for those of FIG. 2, whereto the reader is referredfor their description.

It is specified that in accordance with the teachings provided by thepresent description, the definition of the surfaces of the opticalelements will be subject to numerous dimensional variations in thegeometry of the profiles indicated with the numbers 4, 3, 2, 22, 41 forthe purposes of modifying the upper and lower angles of redistributionof the luminous flow with axis of 90° relative to that of the LEDs 34,in order to meet the different application requirements.

Moreover, it is stressed that the invention and its described variantsmay be subject to numerous changes of a practical-application nature ofthe constructive details (among them, materials used and systems forinterconnecting the elements) without thereby departing from the scopeof the inventive idea as claimed below.

1. A device for redistributing the luminous flow emitted by one or moreLEDs (34) as indicated in FIG. 1 and characterised in that it comprisesa main combined reflection/refraction optical element (1) made of PC andprovided with: a profile indicated by (2) that inferiorly by revolutionaround the axis of symmetry defines a surface characterising a conicalcavity with the vertex positioned in opposite direction relative to theprimary lenses of the LEDs (34), a profile indicated by (4) thatsuperiorly by revolution around the axis of symmetry defines a surfacecharacterising a cupola-shaped cavity with the vertex positioned in thedirection of the primary lenses of the LEDs (34); a profile indicated by(3) that laterally by revolution around the axis of symmetry defines asurface characterising a cone frustum shaped solid with the vertexpositioned in the direction of the primary lenses of the LEDs (34), forthe purposes of the 90° rotation of the optical axis of the photometricsolid emitted as well as to the variation of the upper and lower anglesreferred to said axis relative to that of the LEDs (34).
 2. The deviceas claimed in claim 1, characterised in that said device is providedwith a pin (5) for coupling to other components.
 3. The device asclaimed in claim 2, characterised in that said device is coupled on anoptical protection case (20) by means of an inner cavity (21) forhousing the pin (5) obtained in an inner thickening (23).
 4. The deviceas claimed in claim 3, characterised in that said device is providedwith an optical protection case (20) whose upper thickened region (23)determines a convex surface (22) so constructed as to have opticalcharacteristics of diffuse reflection which concurs in the definition ofthe photometric solid.
 5. The device as claimed in claim 4,characterised in that said device is provided with an optical protectioncase (20) provided with a cavity (24) for connection to a commercialsolid state source.
 6. The device as claimed in claim 5, as indicated inFIG. 2, characterised in that interposed between the surface (22) on thethickened region (23) and the main optical element (1) is an additionaloptical element (40) made of plastic material with added metal-coatinghaving specular reflecting surface (41) which concurs in the definitionof the photometric solid.
 7. The device as claimed in claim 6,characterised in that the optical element (40) is provided with diffusereflecting surface (41) which concurs in the definition of thephotometric solid.
 8. The device as claimed in claim 6, characterised inthat the main optical element (1) and the additional element (40) aredistanced by a spacer element (50).
 9. The device as claimed in claim 7,characterised in that the main optical element (1) and the additionalelement (40) are distanced by a spacer element (50).
 10. The device asclaimed in claim 6, as indicated in FIG. 3 characterised in that themain optical element (1) has in the central part a hole (6) instead ofthe pin (5) in order to allow the insertion of a separate pin (60)provided with a retaining head (61) to reduce the slight luminous flowdispersed along the direction of the optical axis of the LEDs (34). 11.The device as claimed in claim 7, as indicated in FIG. 3 characterisedin that the main optical element (1) has in the central part a hole (6)instead of the pin (5) in order to allow the insertion of a separate pin(60) provided with a retaining head (61) to reduce the slight luminousflow dispersed along the direction of the optical axis of the LEDs (34).12. The device as claimed in claim 8, as indicated in FIG. 3characterised in that the main optical element (1) has in the centralpart a hole (6) instead of the pin (5) in order to allow the insertionof a separate pin (60) provided with a retaining head (61) to reduce theslight luminous flow dispersed along the direction of the optical axisof the LEDs (34).
 13. The device as claimed in claim 9, as indicated inFIG. 3, characterised in that the main optical element (1) has in thecentral part a hole (6) instead of the pin (5) in order to allow theinsertion of a separate pin (60) provided with a retaining head (61) toreduce the slight luminous flow dispersed along the direction of theoptical axis of the LEDs (34).
 14. The device as claimed in claim 10,characterised in that the separate pin (60) is made of metallicmaterial.
 15. The device as claimed in claim 14, characterised in thatthe separate pin (60) is superficially coated with polished nickel. 16.The device as claimed in claim 14, characterised in that the separatepin (60) is superficially coated with polished chrome.
 17. The device asclaimed in claim 11, characterised in that the separate pin (60) is madeof metallic material.
 18. The device as claimed in claim 17,characterised in that the separate pin (60) is superficially coated withpolished nickel.
 19. The device as claimed in claim 17, characterised inthat the separate pin (60) is superficially coated with polished chrome.20. The device as claimed in claim 12, characterised in that theseparate pin (60) is made of metallic material.
 21. The device asclaimed in claim 20, characterised in that the separate pin (60) issuperficially coated with polished nickel.
 22. The device as claimed inclaim 20, characterised in that the separate pin (60) is superficiallycoated with polished chrome.
 23. The device as claimed in claim 13,characterised in that the separate pin (60) is made of metallicmaterial.
 24. The device as claimed in claim 23, characterised in thatthe separate pin (60) is superficially coated with polished nickel. 25.The device as claimed in claim 23, characterised in that the separatepin (60) is superficially coated with polished chrome.
 26. The device asclaimed in claim 1, characterised in that the material whereof the mainoptical element (1) is made is PMMA.
 27. The device as claimed in claim1, characterised in that the material whereof the main optical element(1) is made is glass.
 28. The device as claimed in claim 1,characterised in that the material whereof the main optical element (1)is made is crystal.
 29. The device as claimed in claim 1, characterisedin that the material whereof the optical protection case (20) is made isPMMA.
 30. The device as claimed in claim 1, characterised in that thematerial whereof the optical protection case (20) is made is glass. 31.The device as claimed in claim 1, characterised in that the materialwhereof the optical protection case (20) is made is crystal.
 32. Thedevice as claimed in claim 1, characterised in that the material whereofthe additional optical element (40) is made is metal.
 33. The device asclaimed in claim 1, characterised in that the spacer element (50) isobtained as an appendage of the additional optical element (40).
 34. Thedevice as claimed in claim 1, characterised in that the spacer element(50) is obtained as an appendage of the main optical element (1). 35.The device as claimed in claim 1, as described and illustrated hereinwith reference to the figures of the accompanying drawings and for theaforementioned purposes.
 36. The device according to claim 1 and asdescribed and illustrated herein with reference to the figures of theaccompanying drawings and for the aforementioned purposes.